The present invention relates to a resin molding machine, a method of resin molding and a release film for the machine and the method.
A conventional transfer molding machine is shown in FIG. 44. In the conventional machine, a member to be molded is clamped by an upper die 10a and a lower die 10b, then resin is filled into cavities to mold the member to be molded. The resin, sent from a pot 12, directly contacts inner faces of molding sections of the dies 10a and 10b, a runner and a gate, so the dies 10a and 10b must have enough abrasion-proof ability and durability. The molding dies 10a and 10b are usually made of steel and heat treated.
In the conventional molding machine, solidified resin is stuck in the molding sections, etc., so there are provided ejector pins in the molding dies. To remove the solidified resin on the molding dies, a cleaning step is required for each molding work.
Generally, thermosetting resin, e.g., epoxy resin, phenolic resin, is used. Thus, the molding dies must be heated to a prescribed temperature, so there are heaters in base sections of the molding dies. In the conventional molding machine, the resin directly contacts the molding dies as described above, heat can be directly exchanged between the resin and the dies, so that resin solidification can be accelerated and the molding cycle time can be shortened.
However, the molding dies must have prescribed durability, so it is difficult to machine a hard material so as to make the dies. Furthermore, the ejector pins must be assembled in the dies, so the dies must have a complex structure. Due to the hard material and the complex structure, it is difficult to make the molding dies.